Fiber Collimators Series 60FC-SF
Adjustment_60FC-SF 09.12.2020 © Schäfter+Kirchhoff GmbH
Schäfter+Kirchhoff GmbH Kieler Str. 212 22525 Hamburg, Germany +49 40 85 39 97-0 [email protected] www.sukhamburg.com
5
3. Adjusting the Collimation Setting
Collimation adjustment (adjustment of the coupling lens in z-direction) is a demanding task and should
preferably be performed using a collimating telescope.
To check the collimation setting of the fiber collimator, couple a radiation source of appropriate wavelength into
the fiber connected to the fiber collimator. Direct the beam to a target about half a Rayleigh length z
R
away:
z
R
π
∙
∅
2
beam
=
2
λ
∙8
Here
λ
is the optical wavelength and Ø
beam
the collimated beam diameter (1/e
2
level).
Refer to the laser instruction manual for all instructions regarding laser
safety!
• Avoid staring directly into the laser beam (which can cause permanent
damage to the eyes).
• Avoid staring at the reflected beam from reflective objects.
• Avoid pointing the laser beam to other individuals.
Caution!
When correctly collimated, the laser spot diameter on a target about z
R
/2 away must have approximately the
same diameter such as the beam directly behind the fiber collimator. Additionally, make sure that there is no
focused spot between the collimator and the target at z
R
/2.
The collimation setting is adjusted by gently rotating the knurled ring. Adjust the collimation by minimizing the
size of the laser spot on the target about half the Rayleigh length z
R
away.
Figure 9:
Adjust the focus setting by gently
rotating the knurled ring.
Please do not use the two radially arranged screws. These pin screws are
now used for a different purpose in the 60FC-SF fiber couplers than for the
previous version of the fiber couplers with fine-focusing mechanism 60FC-F.
They are to be used by Schäfter+Kirchhoff only! They are used for adjusting
the backlash of the fine adjustment mechanics and are NOT used for fixing
the collimation setting.
Notice:
